This invention relates generally to power operated mechanisms for adjusting the positions of automotive control pedals, including brake, accelerator and clutch pedals, so that the pedals can be easily reached by both small and large drivers. More particularly, this invention relates to safety switching systems for preventing serious misalignment of the control pedals due to partial failure of the power operating mechanism.
Virtually every new automotive vehicle is now equipped with an air bag mounted in the central portion of the steering wheel. The air bag is provided with means for deploying the air bag in response to rapid deceleration of the vehicle, such as the deceleration which occurs when the vehicle collides with another vehicle or an obstacle.
Recent findings on steering wheel air bag deployments have made it desirable for vehicle manufacturers to offer power pedal adjustment systems which can move the accelerator, brake, and if present, clutch pedals toward or away from the driver. This feature accommodates the needs of taller and shorter drivers while permitting them to be far enough away from the steering wheel to lessen the chance of injury to the driver by the air bag during deployment in an accident.
Current practice is to use a reversible motor mounted on a pedal assembly to slide the assembly toward and away from the driver. The motor rotates a long screw which drives a nut assembled to the pedal, so as to move the pedal in or out. To move the other pedal or pedals, a flexible rotary power cable is used to transmit the torque from the motor to the adjacent pedal or pedals. One possible problem which could occur is that the pedals would not all move together when the driver operates the motor switch, because of failure of the power cable, drive screw, or pedal nut. In this event an unsafe condition of severe pedal misalignment could result, wherein a driver might be able to reach the accelerator pedal easily, but be unable to adequately reach the brake pedal, or vice versa.
One object of the present invention is to provide new and improved mechanical switches and safety switching systems incorporating such switches to prevent serious misalignment of the operating pedals of a vehicle.
Another object is to provide a new and improved switching system which includes slide or rotary type switches connected to and operable by the moveable pedals, together with a switching system for detecting the failure of any pedal to move normally when the other pedal or pedals are being moved by the drive motor, so that the failure of a pedal to move causes the corresponding switch to produce an open circuit, whereby the drive motor is deenergized, whereby the movement of all of the pedals is stopped.
A still further object of this invention is to provide new and improved switches for use in safety switching systems having two switches for two moveable pedals or three switches for three moveable pedals.
A further object is to provide new and improved switches of the foregoing character for preventing serious misalignment of the pedals which are constructed so as to be self adjusting by initial operation of the switching system and the motors in a prescribed manner.
Another object of the present invention is to provide a new and improved method of controlling a motor drive system for adjusting the positions of the control pedals in such a manner as to limit any possible misalignment of the pedals due to malfunctioning of the motor drive system.
A further object is to provide a new and improved method of the foregoing character by detecting any appreciable misalignment of the pedals and by disabling the motor drive system if any serious misalignment is detected.